We can launch F-4s and F-14s loaded for an air defense mission from a CV moored to a pier, with a tail wind. BTDT with the F-4. I expect we can do it with the F/A-18s. I have also seen a light F-4 launch without a catapult from half a British carrier, albeit with 30 knots of wind over the bow. The real question is how much tonnage do you want to carry aloft and how much margin of safety do you want? Of course there are other variables. EMALS, steam catapults, hydraulic catapults. Single engine jet, twin? Turboprops? Pistons? Ejection seats or no? Temperature? Humidity? Sea state? Go grab a NATOPS manual for your favorite aircraft and see what it says.

Aircraft, STOBAR or otherwise, are not some "cookie-cutter" "one-size fits all" interchangeable item.

Some aircraft require very short take-off & landing runs and have low take-off & landing speeds, while others require much greater distances and speeds.

The Russians fly both the Su-27K (Su-33) and the Su-25UTG/UBP from their STOBAR carrier Kuznetsov... the Su-25 has a significantly lower take-off & landing speed than the Su-27, empty or loaded, and thus requires less "wind over deck".

“…Science as it is really practiced, caught up in the turmoil of personalities, with Truth always out of reach, and truths too often limping along, wounded in the turf wars and drive-bys of gangs of Ph.D.-totin’ grant-heads.”
Orson Scott Card: “Future on Ice”

wabpilot wrote:We can launch F-4s and F-14s loaded for an air defense mission from a CV moored to a pier, with a tail wind. BTDT with the F-4.

I recall one of the CVs in San Diego (Independence I think) doing that once as part of a wartime harbor exit exercise, launched an F-14 CAP and IIRC an S-3 to 'sanitize' the harbor approaches before departing.

Nobody informed the public who could see the harbor from their work/home about the exercise (obviously?); apparently they were freaking out about it, at least according to the evening news.

Russian carrier has the mis-applied ski-jump on the bow. The Su-27K or Su-33 is being withdrawn as Kuznetov goes in for her mid-life refit. The newer MiG-29K will replace it. Kuznetov is also reportedly getting two waist catapults.

Cody2 wrote:Is there a minimum maximum speed for a STOBAR carrier? And if so, how slow is too slow?

Could a 20 knot bulk merchant ship be fitted with a flight deck, and operate STOBAR type aircraft? Something similar to the CVE program in WWII, but with modern aircraft and ships.

Even if you use the largest 20kt fleet oiler hull you can find, you might be able to launch something the size of a Skyhawk and you're going to hope its a windy day. STOBAR needs every help it can get which is why everyone with another option uses something else. If you're going with "Merchant" escort carrier, you get a much better bang for your buck going STOVL or even single cat CATOBAR with a scaled down EMALs.

seasick wrote:Russian carrier has the mis-applied ski-jump on the bow. The Su-27K or Su-33 is being withdrawn as Kuznetov goes in for her mid-life refit. The newer MiG-29K will replace it. Kuznetov is also reportedly getting two waist catapults.

2) build a modular structure (something along the lines of what Maersk proposes for its AFSB concept) to accommodate the hangar and such equipment as the arresting gear. Such a structure would have to be strong enough to cope with arrested landings.

Cody2 wrote:Is there a minimum maximum speed for a STOBAR carrier? And if so, how slow is too slow?

Could a 20 knot bulk merchant ship be fitted with a flight deck, and operate STOBAR type aircraft? Something similar to the CVE program in WWII, but with modern aircraft and ships.

Even if you use the largest 20kt fleet oiler hull you can find, you might be able to launch something the size of a Skyhawk and you're going to hope its a windy day. STOBAR needs every help it can get which is why everyone with another option uses something else. If you're going with "Merchant" escort carrier, you get a much better bang for your buck going STOVL or even single cat CATOBAR with a scaled down EMALs.

seasick wrote:Russian carrier has the mis-applied ski-jump on the bow. The Su-27K or Su-33 is being withdrawn as Kuznetov goes in for her mid-life refit. The newer MiG-29K will replace it. Kuznetov is also reportedly getting two waist catapults.

Plus she's about the same size and speed as a rebuilt Midway.

Dassault claims that a Mirage 2000 with two IR missiles and internal fuel can take off, no wind, in about 500 m. They also state that the F-16C and F-18C can, in a similar configuration and conditions, take off in about 460 m and 520 m, respectively. This document claims that a 25,000 lb (11,340 kg) F-104 needs about 4000 ft (1220 m) ground roll to take-off. Given the F-104's high wing loading and likely low achievable lift coefficient, it was probably the most runway-hungry fighter of its generation. Modern fighters have both lower wing loadings (and probably higher achievable lift coefficients) and greater thrust to mass ratios than aircraft of the F-104's generation.

Why is it the same people who promote evidence-based medicine and evidence-based school systems object so strenuously to evidence-based biology and evidence-based climate science?

emc wrote:Dassault claims that a Mirage 2000 with two IR missiles and internal fuel can take off, no wind, in about 500 m. They also state that the F-16C and F-18C can, in a similar configuration and conditions, take off in about 460 m and 520 m, respectively. This document claims that a 25,000 lb (11,340 kg) F-104 needs about 4000 ft (1220 m) ground roll to take-off. Given the F-104's high wing loading and likely low achievable lift coefficient, it was probably the most runway-hungry fighter of its generation. Modern fighters have both lower wing loadings (and probably higher achievable lift coefficients) and greater thrust to mass ratios than aircraft of the F-104's generation.

seasick wrote:Russian carrier has the mis-applied ski-jump on the bow. The Su-27K or Su-33 is being withdrawn as Kuznetov goes in for her mid-life refit. The newer MiG-29K will replace it. Kuznetov is also reportedly getting two waist catapults.

1) What is the term "mis-applied" wrt the ski-jump exactly supposed to mean ?

The Russian Defense Ministry has signed a contract with aircraft maker MiG for the delivery of 20 MiG-29K and four MiG-29KUB carrier-based fighter aircraft, MiG said on Wednesday.

"Defense Minister Anatoly Serdyukov and MiG General Director Sergei Korotkov have signed the contract for the delivery of MiG-29K and MiG-29KUB carrier-based fighters," MiG said in a statement.

MiG wil deliver the aircraft from 2013-2015. The aircraft will operate from Russia's single serving carrier, the Admiral Kuznetsov, with the Northern Fleet based in Murmansk. The value of the deal has not been disclosed.

"The signature of this contract for delivery of these fighters is a real step in fulfilling our program for rearming the forces. The Naval Air Forces will get a modern combat aircraft as good as any in the world," Serdyukov was quoted as saying by his press service.

The contract will guarantee MiG a steady level of work in the medium term, Korotkov said.

The MiG-29K is a navalized variant of the MiG-29 land-based fighter, and has folding wings, an arrester tail-hook, strengthened airframe and multirole capability. It can be armed with a wide variety of air-to-air and air-to-surface weaponry. So far, the aircraft has only been exported to India for use on a refitted Russian-built carrier which is to be delivered at the end of this year.

The Indian Navy has signalled strong support to the naval version of the Tejas Light Combat Aircraft (LCA), even before the indigenous fighter makes its first flight next month. In New Delhi, on Wednesday, the defence ministry’s apex Defence Acquisition Council (DAC) sanctioned the building of eight Naval LCA aircraft by Hindustan Aeronautics Limited (HAL).

“The eight fighters will be a mix of single-seat fighters and twin-seat trainers. The money for these has also been allocated,” says a senior Ministry of Defence official who was at the DAC meeting.

The Rs 3,650 crore Naval LCA programme was sanctioned in March 2003. Two prototypes are almost complete, the first a twin-seat trainer and the second a single-seat fighter. The eight fighters sanctioned on Wednesday are “Limited Series Production” or LSP fighters. These will be used for flight-testing, a painstaking process that could last two years or more. Once flight-testing is completed, HAL will establish a full-scale production line.

The Naval LCA is a crucial cog in the navy’s expansion and, therefore, in India’s increasingly visible maritime strategy. It is designed to fly from an aircraft carrier, a floating airfield that can project Indian power across the oceans. India has already bought Russian MiG-29K medium fighters to equip the INS Vikramaditya (formerly the Gorshkov) an aircraft carrier acquired from Russia. But another two (and possibly three) indigenous Vikrant-class aircraft carriers being built at Cochin Shipyard Ltd will field the Naval LCA, along with a medium fighter.

With the first of these, INS Vikrant, at an advanced stage of construction in Kochi, the navy is keen that development of the Naval LCA proceeds alongside. Earlier this month, the normally soft-spoken navy chief, Admiral Nirmal Verma, publicly criticised the Aeronautical Development Agency (ADA oversees the LCA programme) for placing the Naval LCA programme on the back burner, while focusing on the air force version of the Tejas.

The admiral’s words have goaded HAL into action. Business Standard has been told that the Naval LCA will take to the air in March, a landmark event for the navy.

“The Naval LCA will definitely fly in March. We are doing ground runs and starting low-speed taxi trials, in which the fighter rolls on the runway under its own power. Then we will do some high-speed taxi trials, in which the fighter will accelerate to take-off speed; but when its nose lifts off the ground, we will slow down without actually taking off. Only after that will the first flight actually take place,” says PV Deshmukh, HAL’s officiating CMD.

The Rs 10,397 crore air force Tejas project has obtained initial operational clearance (IOC), and will soon join the IAF’s fleet. But the Naval Tejas presents additional design challenges, such as being able to take off from an aircraft carrier’s ski-jump after accelerating for just 200 metres. Even more challenging are repeated carrier deck landings, in which a hook on the aircraft snags on an “arrestor cable” on the deck, forcing the aircraft to a standstill in just 90 metres. These landings, in which the fighter slams into the carrier deck at more than 7 metres per second, are often described as “controlled crashes.”

The navy and ADA will extensively test the Naval LCA on land before venturing onto an aircraft carrier at sea. A Shore-Based Test Facility (SBTF) has been created in Goa, which replicates the dimensions and conditions of a carrier deck, including the arrestor and gear that brings the aircraft to a quick halt; and the optical landing system that allows the pilot to “aim” his fighter at the arrestor wire spread out on the carrier deck. After extensive SBTF testing, the Naval LCA will face the crucial challenge of landing and taking off from an actual aircraft carrier.

The navy’s two prototypes and eight LSP fighters will be powered by General Electric GE F-404 engines. Meanwhile, ADA has selected the more advanced and powerful GE F-414 engine for the LCA Mark II. This engine will also power future Naval LCAs. With 15 per cent more thrust, the GE F-414 will be useful in taking off from an aircraft carrier deck.

The Pentagon last month relaxed the performance requirements for the Joint Strike Fighter, allowing the Air Force F-35A variant to exceed its previous combat radius -- a benchmark it previously missed -- and granting the Marine Corps F-35B nearly 10 percent additional runway length for short take-offs, according to Defense Department sources.

On Feb. 14, the Joint Requirements Oversight Council -- in a previously unreported development -- agreed to loosen select key performance parameters (KPPs) for the JSF during a review of the program convened in advance of a high-level Feb. 21 Defense Acquisition Board meeting last month, at which the Pentagon aimed to reset many dimensions of the program, including cost and schedule.

Pentagon sources said a memorandum codifying the JROC decisions has not yet been signed by Adm. James Winnefeld, the vice chairman of the Joint Chiefs of Staff and the JROC chair.

Sources familiar with the changes, however, said the JROC -- which also includes the service vice chiefs of staff -- agreed to adjust the "ground rules and assumptions" underlying the F-35A's 590-nautical-mile, combat-radius KPP.

Last April, the Pentagon reported to Congress in a selected acquisition report that "based on updated estimate of engine bleed," the F-35A would have a combat radius of 584 nautical miles, below its threshold -- set in 2002 -- of 590 nautical miles.

To extend the F-35A's combat radius, the JROC agreed to a less-demanding flight profile that assumes near-ideal cruise altitude and airspeed, factors that permit more efficient fuel consumption. This would allow the estimate to be extended to 613 nautical miles, according to sources familiar with the revised requirement.

The estimated combat radius of the short-take-off variant, which is being developed for the Marine Corps, is 15 percent lower than the original JSF program goal even though the aircraft is slated to carry fewer weapons than originally intended, according to the April report.

The short-take-off-and-landing KPP before the JROC review last month was 550 feet. In April 2011, the Pentagon estimated that the STOVL variant could execute a short take-off in 544 feet while carrying two Joint Direct Attack Munitions and two AIM-120 missiles internally, as well as enough fuel to fly 450 nautical miles. By last month, that take-off distance estimate grew to 568 feet, according to DOD sources.

The JROC, accordingly, agreed to extend the required take-off distance to 600 feet, according to DOD officials.

The JROC review of the F-35 program last month was held in accordance with a policy adopted by the council in June 2010, which requires a reassessment of requirements for all programs with cost growth exceeding 25 percent of the original program baseline. One goal of the policy is to determine whether a decision to relax requirements should be made to improve acquisition cost and schedule estimates. -- Jason Sherman

The UK Ministry of Defence is continuing research to refine a hybrid shipboard rolling vertical landing (SRVL) technique, potentially to be employed as the primary recovery mode for Lockheed Martin F-35B Joint Strike Fighters operating from the Royal Navy's two Future Aircraft Carriers (CVF).

A programme of MoD-sponsored research work, including technical advice from the Defence Science and Technology Laboratory (Dstl), has already concluded that SRVL would offer a significant increase to the F-35B's payload "bring back", without any fundamental platform or safety issues. However, further investigations are planned to address a range of optimisation and integration issues, says Martin Rosa, JSF technical co-ordinator in the Dstl's air and weapon systems department.

An SRVL involves a short take-off and vertical landing aircraft performing a "running landing" on to the carrier flightdeck, using air speed to provide wingborne lift to complement engine thrust. The touchdown position on an axial flightdeck is similar to that of a conventional carrier - about 45m (150ft) from the stern, but no arrestor gear is required, as the aircraft uses its brakes to come to a stop within a distance of 90-150m. The technique could allow an F-35B to recover with an extra 907kg (2,000lb) of weapons and fuel, or reduce propulsion system stress and increase engine life.

The Dstl began work to examine the feasibility of employing the SRVL manoeuvre in the late 1990s. Following a series of simulation-based studies, the MoD's investment approvals board in July 2006 endorsed the requirement as part of its F-35B-based Joint Combat Aircraft programme.

Speaking at the Royal Aeronautical Society's International Powered Lift conference in London in July, Rosa said SRVL studies have shown that "a way forward exists to achieving operationally useful increases in bring-back, compared to a vertical landing, on board CVF with an appropriate level of safety". But "uncertainties remain in terms of the scope of an operational clearance and the potential impact on the sortie generation rate for CVF".

Qinetiq used its VAAC Harrier testbed to perform representative land-based flight trials and a ship-based SRVL demonstration aboard the French navy's aircraft carrier Charles de Gaulle last year.

Rosa said past work has also identified a promising visual landing aids (VLA) concept optimised for SRVL and stabilised against deck motion. "We will continue to mature the SRVL-optimised VLA arrangements, look at the possible 'tuning' of the JSF flight-control laws, and further study the effect of SRVL on the CVF sortie generation rate," he said. The capability's full scope will be confirmed after flight trials from the 65,000t vessels, which are due to enter service in 2014 and 2016, respectively.

Other forthcoming work includes optimisation of the approach profile, agreement on the optimal post-touchdown technique, and mitigation for failure cases, such as a burst tyre on touchdown.

“…Science as it is really practiced, caught up in the turmoil of personalities, with Truth always out of reach, and truths too often limping along, wounded in the turf wars and drive-bys of gangs of Ph.D.-totin’ grant-heads.”
Orson Scott Card: “Future on Ice”